Interface mechanisms are used on vehicles to control various vehicle components or subsystems. Throttle controls are used to control vehicle engines. Dual lever throttle controls are commercially available wherein one throttle lever sets a desired minimum engine speed and a second lever sets a desired maximum engine speed. With such a dual lever throttle control, there can be a combination of positions whereby the operator cannot tell which control will govern engine commands from visual or physical position of the levers. For example, if the engine minimum lever is set above the engine maximum lever, it will not be clear to the operator what the engine speed will be. It is desired to provide a dual lever throttle control which avoids ambiguous control positions.